A bit of new that's about a month old, yet it's important enough to mention.

"SciFi Wire is reporting on a rumor that work has begun on a script for a second movie based on C.S. Lewis’ Chronicles of Narnia.
Making of the second movie appears to depend entirely on the success of the first one, though they may actually film the next two at that point.
Its not clear from the reports which book the second film is being based on, though most likely it would be Prince Caspian."